Method and apparatus for patient loading and unloading

ABSTRACT

A method and apparatus of a positioning system are described to position an upper-half of a body relative to a head-end of a couch. The positioning system may be a patient positioning system and may include a treatment couch, a leg rest coupled to the treatment couch, and a drive mechanism coupled to the leg rest. The patient positioning system may also include a treatment couch, having a base portion of a treatment couch and plurality of detachable portions of the treatment couch. The plurality of detachable portions to adjust a height of the treatment couch to accommodate differing heights of patients.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/339,717 filed Jan. 24, 2006.

TECHNICAL FIELD

Embodiments of the present invention pertain to the field of patientpositioning assembly for medical operations.

BACKGROUND

Treatment couches have been used in various medical operations. Someexamples of treatment couches are surgery tables, operating tables,dentist chairs, and treatment couches for radiation treatment systems.Some examples of radiation treatment systems are gantry-based radiationtreatment system and robot-based linear accelerator system. Treatmentcouches, in general, may be used to support a patient during thesemedical operations. Treatment couches may also be used to position apatient into a specific position in a treatment room. For example, atreatment couch may be used to position a patient with respect to alinear accelerator or other radiation sources for both gantry-based androbot-based treatment systems.

Another conventional design of a treatment couch used for medicaloperations is a reclining chair. It has two portions; a base portion,and a reclining portion. The reclining portion of the reclining chairallows a patient to sit back during a scanning procedure. In oneconventional design, the reclining portion and the base portion movetogether to recline a patient backwards for treatment. In anotherconventional design, the reclining portion and the base portion may movein a folding and unfolding motion to and from one another. This foldingand unfolding motion allows a patient to sit on the chair for patientloading purposes, and then allows the patient to sit back, or reclineback for patient treatment purposes. These folding functions, however,do not include any mechanism to physically move the patient towards thehead-end of the chair or table, or to physically move the patient to aspecific position on the table or chair. These conventional designsmerely position the patient forwards and backwards with respect to anupright sitting position of the reclining chair.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings.

FIG. 1A illustrates one embodiment of a treatment couch having a legrest and drive mechanism in a loading position.

FIG. 1B illustrates another embodiment of a treatment couch having a legrest and drive mechanism in a treating position.

FIG. 2 illustrates one embodiment of a motorized drive mechanismincluding a rack and pinion gear.

FIG. 3 illustrates one embodiment of a drive mechanism including amotorized telescopic ball screw drive system mounted on a centerline ofthe treatment couch.

FIG. 4 illustrates one embodiment of a drive mechanism including asingle motorized ball screw drive system mounted on an off-center lineof the treatment couch.

FIG. 5 illustrates one embodiment of a drive mechanism including dualmotorized ball screw drive system, including one motor, mounted onoff-center lines of the treatment couch.

FIG. 6A illustrates another embodiment of a drive mechanism includingdual motorized ball screw drive system, including two motors, mounted onoff-center lines of the treatment couch.

FIG. 6B illustrates the drive mechanism of FIG. 6A including anextension mounting area.

FIG. 7A illustrates one embodiment of a treatment couch including a legrest with one pivot point.

FIG. 7B illustrates another embodiment of a treatment couch including aleg rest with two pivot points.

FIG. 7C illustrates a single articulation of the one pivot point of theembodiment of FIG. 7A.

FIG. 7D illustrates a double articulation of the two pivot points of theembodiment of FIG. 7B.

FIG. 8 illustrates one embodiment of a treatment couch including a baseportion and plurality of detachable portions.

FIG. 9A illustrates one embodiment a patient positioning system,including a treatment couch, a motorized leg rest, and a robotic arm,and a patient at two positions on the treatment couch while thetreatment couch is in a non-horizontal loading position.

FIG. 9B illustrates the embodiment of FIG. 9A while the treatment couchis in a horizontal treatment position.

FIG. 10A is a perspective drawing illustrating a patient in a firstposition of a workspace of a radiation treatment system including a setof spatial nodes at which to position the radiation source, inaccordance with an exemplary embodiment of the invention.

FIG. 10B is a perspective drawing illustrating the patient in a secondposition of the workspace of the radiation treatment system, inaccordance with the embodiment of FIG. 10B.

FIG. 11A is an elevational side view illustrating a cross-section of aworkspace of a radiation treatment system including a node set and anincreased node set, in accordance with an embodiment of the invention.

FIG. 11B is an elevational end view illustrating a cross-section of aworkspace of a radiation treatment system including a node set and anincreased node set, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION

The following description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent invention. It will be apparent to one skilled in the art,however, that at least some embodiments of the present invention may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present invention. Thus, the specific details set forth are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the spirit and scope ofthe present invention.

Embodiments of a method and apparatus of a positioning system aredescribed to position an upper-half of a body relative to a head-end ofa couch. In one embodiment, the positioning system may be a patientpositioning system. The patient positioning system may include atreatment couch, a leg rest coupled to the treatment couch, and a drivemechanism coupled to the leg rest. The drive mechanism moves the legrest in one translational direction to adjust an upper-half of a body ofa patient with respect to a head-end of the treatment couch. In anotherembodiment, the patient positioning system may include a treatmentcouch, having a base portion of a treatment couch and a plurality ofdetachable portions of the treatment couch. One detachable portion iscoupled to the base portion of the treatment couch. The plurality ofdetachable portions are used to adjust a height of the treatment couchto accommodate differing heights of patients. In another embodiment, thepatient positioning system may include a treatment couch, having a baseportion of a treatment couch and a ratchet portion of the treatmentcouch coupled to the base portion of the treatment couch. The ratchetportion is used to adjust a height of the treatment couch to accommodatediffering heights of patients.

It should be noted that the embodiments described herein have beendescribed with reference to a body of a human patient for purposes ofmedical treatment. The term ‘patient’, as used herein, may refer to ahuman patient, or an animal patient. The embodiments described hereinare not limited to adjusting or positioning a body of a patient formedical purposes, but may include adjusting or positioning a body (e.g.,human or animal body) on a couch (e.g., chair, table, or other supportmembers) for other non-medical purposes. Similarly, it should be notedthat the embodiments described herein are not limited to a treatmentcouch used for purposes of medical treatment, but may also include acouch used for other (e.g., non-medical) purposes.

FIG. 1A illustrates one embodiment of a treatment couch having a legrest and drive mechanism in a loading position. Patient positioningsystem 100 of FIG. 1A includes treatment couch 101, leg rest 102, drivemechanism 103, and extension mounting area 104. Treatment couch 101 iscoupled to leg rest 102. Drive mechanism 103 is coupled to leg rest 102and extension mounting area 104. Alternatively, drive mechanism 103 maybe coupled to treatment couch 101 and leg rest 102. Extension mountingarea 104 is coupled to treatment couch 101. Alternatively, extensionmounting area 104 may be coupled to the leg rest 102.

The leg rest 102 of FIG. 1A is positioned at a first position on thetreatment couch 101, position 107. When the leg rest 102 is positionedat position 107 it may be towards the bottom-end 109 of the treatmentcouch 101. Position 107 may be used for loading and/or unloading apatient onto and/or from treatment couch 101. It should be noted thatpatient, as used herein, may be a human patient, or alternatively, ananimal patient. Drive mechanism 103 may be used to move the leg rest 102in one translational direction, x-direction 106, relative to a head-end105 of the treatment couch 101. In other words, the drive mechanism 103may move the leg rest 102, which supports the lower-half of thepatient's body, up and down with respect to the head-end 105. In effect,moving the leg rest 102 towards and/or from the head-end 105 of thetreatment couch 101, the patient positioning system 100 adjusts anupper-half of the patient relative to the head-end 105 of the treatmentcouch 101.

In one embodiment, position 107 may be a loading position.Alternatively, position 107 may be a treating position for a patientwhose height requires no adjustment of his/her upper-half of his/herbody on the treatment couch 101. The loading position may be when thetreatment couch 101 is tilted approximately 42 degrees from aperpendicular axis to the floor of the treatment room. In anotherembodiment, the loading position may be at approximately 50 degrees. Bylowering the loading position from 42 degrees to 50 degrees, thedistance that the leg rest must travel from the loading position to thetreating position may be lowered from approximately 28 inches to 24inches. These exemplary embodiments of 42 degrees and 50 degrees are forloading a patient in a non-horizontal position; however, it should alsobe noted that the loading position may be in a horizontal position, 90degrees from the perpendicular axis to the floor of the treatment room.Alternatively, other degrees of tilt for the loading position may beused based on patient comfort.

FIG. 1B illustrates another embodiment of a treatment couch having a legrest and drive mechanism in a treating position. Patient positioningsystem 100 of FIG. 1B includes treatment couch 101, leg rest 102, drivemechanism 103, and extension mounting area 104. Treatment couch 101 iscoupled to leg rest 102. Drive mechanism 103 is coupled to leg rest 102and extension mounting area 104. Alternatively, drive mechanism 103 maybe coupled to treatment couch 101 and leg rest 102. Extension mountingarea 104 is coupled to treatment couch 101. Alternatively, extensionmounting area 104 may be coupled to the leg rest 102.

Leg rest 102 of FIG. 1B is positioned at a second position on thetreatment couch 101, position 108. When the leg rest 102 is positionedat position 108 it may be towards the head-end 105 of the treatmentcouch 101. Position 108 may be used for treating a patient on treatmentcouch 101. Alternatively, position 108 may be used as a horizontalloading position.

In one embodiment, the treating position 108 may be where the head ofthe patient is positioned or aligned so that there is substantially nospace between the head of the patient and the head-end 105 of thetreatment couch 101. In one embodiment, the treating position 108 may bewhere the head of the patient is located within the head extension 111.Head extension 111 may be less in width than the treatment couch 101 toallow a radiation source to be positioned closer to the patient's head.It should be noted, however, that the treatment couch 101 may notinclude a head extension 111 and the patient's head may be positioned tohave a certain distance (e.g., 908) between the head of the patient andthe head-end 105, for example, within six inches. This may allow aradiation source to be positioned with respect to the head of thepatient with minimal interference from the treatment couch 101, orwithout any interference from the treatment couch 101. For example, if ashorter patient (e.g., one percentile female height of 58.1 inches). Inone embodiment, after a patient is loaded onto the treatment couch 101in position 107, the leg rest 102 may be moved in the translationalx-direction 106 up or down (away from and towards the head-end 106) toposition the patient on the treatment couch to a treating position,position 108. However, position 108 may be used as a loading position.The patient may be loaded onto the treatment couch in position 108, andthen, the leg rest 102 may be moved in the translational x-direction 106up or down (away from or towards the head-end 106) to position thepatient on the treatment couch to a treating position, position 107. Theloading position may be a seated position where the treatment couch istilted at an angle, or alternatively, a horizontal position where thetreatment couch is parallel to the ground of the treatment room.

It should be noted that the term treating position, as used herein, isused to describe how the patient is positioned or adjusted on thetreatment couch 101 relative to the head-end 106 of the treatment couch101. The term treatment position, as used herein, is used to describehow the treatment couch 101 is positioned in a treatment room and/orrelative to a radiation source. It should also be noted that thetreatment positions within a treatment room may be a seated positionwhere the treatment couch is tilted at an angle from the ground of thetreatment room (as illustrated in FIG. 1A), or alternatively, ahorizontal position where the treatment couch is substantially parallelto the ground of the treatment room (as illustrated in FIG. 1B). Inother words, the patient may be positioned (or adjusted) on thetreatment couch 101 relative to a head-end 106, and positioned in thetreatment room (by positioning the treatment couch 101). Thesepositioning operations may be done concurrently or subsequently to oneanother.

As previously described, drive mechanism 103 may be used to move the legrest 102 in one translational direction, x-direction 106, relative to ahead-end 105 of the treatment couch 101. In other words, the drivemechanism 103 may move the leg rest 102, which supports the lower-halfof the patient's body, up and down with respect to the head-end 105. Ineffect, by moving the leg rest 102 towards and/or from the head-end 105of the treatment couch 101, the patient positioning system 100 adjustsan upper-half of the patient relative to the head-end 105 of thetreatment couch 101. In one embodiment, position 108 may be a treatingposition.

In one embodiment, the treating position 108 may be where the head ofthe patient is positioned or aligned so that there is substantially nodistance between the head of the patient and the head-end 105 of thetreatment couch 101. In one exemplary embodiment, the distance betweenthe head of the patient and the head-end 105 for the treating position108 may have a range of approximately zero to six inches. This may allowa radiation source to be positioned with respect to the head of thepatient with minimal interference from the treatment couch 101, orwithout any interference from the treatment couch 101. For example, if ashorter patient (e.g., 1 percentile female height of 58.1 inches) isloaded onto the treatment couch 101 in position 107, the patient's headwill not be aligned or positioned at the top (e.g., head-end 105) of thetreatment couch 101 because of the height of the shorter patient.However, by moving the leg rest 102 of the treatment couch 101 towardsthe head-end 105 of the treatment couch 101 (e.g., from position 107 toposition 108), the patient's head may become aligned or positioned atthe top (e.g., head-end 105) of the treatment couch 101.

In one embodiment, a sliding member 110 may be coupled to the leg rest102. The slide member 110 may be attached to the leg rest so that it theslide member 110 moves with the translational motion of the leg rest 102in the x-direction 106. Slide member 110 may be a thin back piece. Theslide member 110 may be used to reduce the friction between theupper-half of the patient's body and the treatment couch 101. The slidemember 110 may also be used to prevent the upper-half of the patient'sback from directly lying on the treatment couch 101 to help prevent thepatient from getting pinched between the leg rest 102 and the treatmentcouch 101 as the leg rest 102 moves from one position to another in thex-direction 106.

In one exemplary embodiment, a mask may be placed on the patient's headto secure the patient to the treatment couch 101 and prevent the headfrom moving during treatment. The mask may be coupled to a mountingdevice, which secures the mask to the treatment couch 101. In order tosecure the mask to the patient's head, the patient's head must bealigned and positioned correctly towards the head-end 105 of thetreatment couch. By moving the leg rest 102 using the drive mechanism103, the upper-half of the patient may be adjusted relative to thehead-end 105 of the treatment couch 101, and may be positioned to allowthe mask to be secured or mounted to the treatment couch 101.

Extension mounting area 104 of FIGS. 1A and 1B may be used to mount thetreatment couch 101 to a stand, to a robotic arm, or to a motorizedmechanism. It should be noted that the extension mounting area may alsobe disposed at another location along the periphery of the treatmentcouch 101 other than as shown in FIGS. 1A and 1B, such as at thebottom-end 109 of treatment couch 101. In one embodiment, the treatmentcouch 101 is coupled to a robotic arm.

In one exemplary embodiment, the robotic arm may be used to position thetreatment couch in five degrees of freedom. The five degrees of freedommay include two rotational axes for translational movements alongmutually orthogonal x-, and y-horizontal coordinate axes; and threerotational axes for roll-, pitch-, and yaw-rotational movements aboutx-, y-, and z-axes, respectively. In another embodiment, the robotic armmay position the treatment couch using six degrees of freedom, forexample, five rotational degrees of freedom as previously described, andone substantially vertical, linear degree of freedom. The onesubstantially vertical, linear degree of freedom may include asubstantial linear axis for translation along a substantially verticalline in a z-coordinate axis perpendicular to the horizontal, x-, andy-coordinate axes. In another embodiment, the robotic arm may positionthe treatment couch using seven degrees of freedom, six rotationaldegrees of freedom, and one substantially vertical, linear degree offreedom. Alternatively, the robotic arm may include less than fivedegrees of freedom, such as two or three degrees of freedom.

The robotic arm may be coupled directly to the treatment couch 101 in amounting region, or alternatively to the extension mounting area 104.Alternatively, if the patient treatment couch 101 is sufficientthickness in the mounting region, the robotic arm may be mounteddirectly to an edge side of the treatment couch without the use ofextension mounting area. The mounting of robotic arm on extensionmounting area 104 (or, alternatively, on to edge side) may be used toallow the robotic arm to be out of the imaging field of view for allsupported treatment positions. It should also be noted that drivemechanism 103 may be mounted to a mounting region of the treatment couch101, or alternatively, to the extension mounting area 104.

FIG. 2 illustrates one embodiment of a motorized drive mechanismincluding a rack and pinion gear. The rack and pinion gear includes amotor 201, rack 202, and pinion 203. The rack and pinion gear is used toconvert rotational motion of the motor 201 in the y-rotational direction206 about axis 212 into linear motion of the leg rest 102 or treatmentcouch 101 in the x-direction 106. Motor 201 is mounted to extensionmounting area 104 via mounting device 205. The motor 201 rotates pinion203. Alternatively, the pinion 203 may be attached to a shaft (e.g.,drive shaft 211), which is attached to the motor 201. The pinion 203 isoperatively coupled to the rack 202. The rack 202 may include multipleteeth in which the pinion 202 may engage. As the motor 201 rotates thepinion 203 (or drive shaft 211 coupled to the pinion 203) in they-rotational direction 206 about axis 212, the pinion 203 engages theteeth of the rack 202, causing the rack 202 to move linearly in thex-direction 106. In one embodiment, the rack is coupled to the leg rest102 (e.g., via slide member 210). In another embodiment, the rack iscoupled to the treatment couch 101, and the treatment couch movesrelative to a leg rest 102.

In one embodiment, as illustrate in FIG. 2, the motor 201 is mounted tothe extension mounting area 104 of the treatment couch 101, and the rack202 is mounted to slide member 210. The slide member 210 may move alonga rail slide mounted to the treatment couch 101. The rail slide may beused to facilitate translational motion of the leg rest 102 relative toa head-end 105 of the treatment couch 101. The rail slide may be mountedto the external surface of the treatment couch 101, or alternatively, itmay be embedded within the treatment couch 101.

In another embodiment, rack 202 may be coupled directly to the treatmenttable 101, in which case, the pinion 203 drives the rack 202 to move thetreatment couch 101 relative to the leg rest 102 in the x-direction 106.Alternatively, slide member 210 may be coupled to the leg rest 102, inwhich case, the pinion 203 drives the rack 202 to move the leg rest 102relative to the treatment couch 101 in the x-direction 106.

In one embodiment, the motorized drive mechanism including a rack andpinion gear may be used to adjust an upper-half of a patient relative tothe head-end 105 of the treatment couch 101. For example, the rack andpinion gear of FIG. 2 may be used to position the leg rest 102 inmultiple positions, such as loading position 208, and treating positions209(1)-209(N), where N is a positive integer. The motorized drivemechanism including the rack and pinion gear may position the patient tomultiple treating positions 209, which allows a patient to be positionedto a specific position on the treatment couch 101 regardless of theheight of the patient. For example, the head of a patient may bepositioned to a treating position or mask-mounting position (aspreviously described) on the treatment couch 101 regardless of theheight of the patient. In one embodiment, the motorized drive mechanismincluding the rack and pinion gear may allow the leg rest to travel upto approximately 22 inches in the x-direction 106. In anotherembodiment, the drive mechanism may allow the leg rest to travel up toapproximately 28 inches. Alternatively, the drive mechanism may allowthe leg rest to travel up to approximately 45 inches. It should be notedthat this distance may be longer, depending on the length of thetreatment couch 101. It should be noted, however, that in othernon-treatment applications, the leg rest and corresponding drivemechanism may be designed to allow travel of the leg rest up to longerdistances without departing from the scope of this invention.

The embodiments described herein may accommodate a majority of differingheights of people, such as a range from one percentile female to theninety-nine percentile male. In one exemplary embodiment, the onepercentile female to the ninety-nine percentile male is a range ofapproximately 58.1 to 75.6 inches. Rack and pinion gears are known bythose of ordinary skill in the art, and accordingly, additional detailsregarding their operation and configurations have not been included soas to not obscure the embodiments of the present invention.

FIG. 3 illustrates one embodiment of a drive mechanism including amotorized telescopic ball screw drive system 300 mounted on a centerlineof the treatment couch. The motorized telescopic ball screw drive systemincludes motor 201, belt 301, and telescopic ball screw 302. Themotorized telescopic ball screw drive system is used to convertrotational motion of the motor 201 about the axis 312 into linear motionof the leg rest 102 or treatment couch 101 in the x-direction 106. Motor201 is mounted to treatment couch 101 via mounting device 205. Belt 301is coupled to the motor 201 and the telescopic ball screw 302. The motor201 rotates one end of the belt 301 via a drive shaft 211. The other endof the belt 301 rotates the telescopic ball screw 302. The telescopicball screw 302 is coupled to mounting device 303. Mounting device 303 issecured to the treatment couch 101. As the telescopic ball screw 302 isrotated a portion of the telescopic ball screw 302 moves up and downrelative to the head-end 105 of the treatment couch 101 in thex-direction 106. The telescopic ball screw 302 is coupled to the legrest 102. Telescopic ball screw 302 may be coupled to the leg rest 102by a T-shaped bracket (not illustrated) and a slide member 306. Slidemember 306 moves along rail slide 304. The rail slide 304 may be used tofacilitate translational motion of the leg rest 102 relative to ahead-end 105 of the treatment couch 101. Rail slide 304 may be mountedto the external surface of the treatment couch 101, or alternatively, itmay be embedded within the treatment couch 101, as illustrated in FIG.3. Accordingly, as the motor 201 rotates, motor 201 drives the belt 301,which in turns drives the telescopic ball screw 302 in a linear,translational direction (e.g., 106), which in turn drives the leg rest102 (via slide member 306 and rail slide 304) in a linear, translationaldirection (e.g., 106). The surface of the telescopic ball screw 302includes grooves or threads. The motorized telescopic ball screw drivesystem 300 includes a ball screw nut or ball screw car. The ball screwnut includes ball bearings (e.g., recirculating channel of balls) thatpass through the large grooves or threads on the telescopic ball screw302 to facilitate motion of ball screw nut along the telescopic ballscrew 302. In one exemplary embodiment, the ball screws may be ballscrews manufactured by HIWIN Corporations of Mt. Prospect, Ill. Inanother embodiment, a linear actuator may be used instead of atelescopic ball screw drive system. Alternatively, other drive systemsknown by those of ordinary skill in the art may be used, such as apneumatic cylinder, or a regular drive screw driven by a stepper motor.

In one embodiment, the drive mechanism including a motorized telescopicball screw drive system 300 may be housed under the extension mountingarea (e.g., bracket) 104. Extension mounting area 104 may include araised offset mount 305 for clearance of the drive mechanism. In anotherembodiment, the drive mechanism may be embedded within the treatmentcouch 101 either on a centerline 305 or on an off-center line of thetreatment couch 101 so that the raised offset mount 305 may not beneeded for clearance of the drive mechanism. Alternatively, the drivemechanism may be mounted to the external surface of the treatment couch101 on an off-center line so that the raised offset mount 305 may not beneeded for clearance of the drive mechanism. The drive mechanism mayalso be mounted to the extension area 104, or alternatively, to the legrest 102 (not illustrated in FIG. 3).

In one embodiment, the drive mechanism including a motorized telescopicball screw drive system 300 may be used to adjust an upper-half of apatient relative to the head-end 105 of the treatment couch 101. Forexample, the motorized telescopic ball screw drive system 300 of FIG. 3may be used to position the leg rest 102 in multiple positions, such asa loading position, and one or more treating positions. The drivemechanism including the motorized telescopic ball screw drive system mayposition the patient to multiple treating positions, which allows apatient to be positioned to a specific position on the treatment couch101 regardless of the height of the patient. For example, the head of apatient may be positioned to a treating position or mask-mountingposition (as previously described) on the treatment couch 101 regardlessof the height of the patient. In one embodiment, the telescopic ballscrew may allow the leg rest to travel up to approximately 45 inches inthe x-direction 106. Alternatively, the drive mechanism may allow theleg rest to travel up to approximately 28 inches. The embodimentsdescribed herein may accommodate a majority of the differing heights ofpeople, such as a range from one percentile female (e.g., 58.1 inches)to the 99 ninety-nine percentile male (e.g., 75.6 inches). Motorizedtelescopic ball screw drive systems are known by those of ordinary skillin the art, and accordingly, additional details regarding theiroperation and configurations have not been included so as to not obscurethe embodiments of the present invention. Alternatively, the motorizeddrive mechanism may be a linear actuator, a pneumatic cylinder, aregular drive screw driven by a stepper motor, or other actuators knownby those of ordinary skill in the art.

FIG. 4 illustrates one embodiment of a drive mechanism including asingle motorized ball screw drive system 400 mounted on an off-centerline of the treatment couch. The single motorized ball screw drivesystem 400 includes motor 201, belt 301, ball screw 402, and ball screwnut 307. The single motorized ball screw drive system 400 is used toconvert rotational motion of the motor 201 about axis 412 into linearmotion of the leg rest 102 or treatment couch 101 in the x-direction106. Motor 201 is mounted to treatment couch 101 via mounting device205. The single ball screw 402 may include a housing, which may bemounted to the external surface of the treatment couch 101 using one ormore mounting devices (e.g., 308), or alternatively, embedded within thetreatment couch 101, as illustrated in FIG. 4. Alternatively, the singleball screw 402 may be mounted directly to the treatment couch 101without the housing. A single ball screw 402 may be mounted to thetreatment couch 101 on an off-center line 406 of the treatment couch101. The off-center line 406 may be an offset distance 407 from thecenterline 305 of the treatment couch 101. In one exemplary embodiment,the offset distance 407 may have a range of approximately zero toapproximately twelve inches from the centerline 305. Alternatively,other offsets may be used. The single ball screw 402 is coupled to slidemember 306 via ball screw nut 307. Belt 301 is coupled to the motor 201and the single ball screw 402. The motor 201 rotates one end of the belt301 via a drive shaft 211. The other end of the belt 301 rotates thesingle ball screw 402.

Ball screw nut 307 includes a hole in which the single ball screw 402passes. The surface of the ball screw 402 include grooves or threads,and the ball screw nut 307 includes ball bearings (e.g., recirculatingchannel of balls) that pass through the grooves or threads of the ballscrew 402 to facilitate motion of ball screw nut 307 along the singleball screw 402. It should be noted that the ball bearings of the ballscrew nut 307 are smaller than the grooves of the ball screw 402. As thesingle ball screw 402 is rotated by motor 201 via belt 301, ball screwnut 307 moves along the single ball screw 402 relative to the head-end105 of the treatment couch 101 in the x-direction 106. Ball screw nut307 is coupled to slide member 306, which is coupled to the leg rest102. As the ball screw nut 307 moves along the single ball screw 402,the leg rest 102 moves up and down along the one translationaldirection, x-direction 106, relative to the head-end 105 of thetreatment couch 101, via slide member 306. In other words, as the motor201 rotates, motor 201 drives the belt 301, which in turns rotates thesingle ball screw 402, which in turn drives the ball screw nut 307 in alinear, translational direction (e.g., 106), which in turn drives theleg rest 102 (via slide member 306) in a linear, translational direction(e.g., 106). In another embodiment, a regular drive screw may be used inplace of the ball screw. The regular drive screw and corresponding nutor car includes threads to facilitate motion of the nut or car along thescrew. Alternatively, other actuators known by those of ordinary skillin the art may be used in this configuration, such as a linear actuator,a pneumatic cylinder, a regular drive screw driven by a stepper motor.

It should be noted that due to the fact that the forces in theoff-center line mounting (e.g., off-center line 406) may be higher thanforces in the centerline mounting (e.g., center line 305), the size ofthe drive mechanism and slide member may need to be increased tocompensate or overcome the offset imbalance. By using two drives inparallel, the sizing of lead screws (e.g., ball screws) may be reduced,as described below with respect to FIG. 5.

In one embodiment, the drive mechanism including a single motorized ballscrew 402 may be used to adjust an upper-half of a patient relative tothe head-end 105 of the treatment couch 101. For example, the singlemotorized ball screw 402 of FIG. 4 may be used to position the leg rest102 in multiple positions, such as a loading position, and one or moretreating positions. The drive mechanism including the single motorizedball screw may position the patient to multiple treating positions,which allows a patient to be positioned to a specific position on thetreatment couch 101 regardless of the height of the patient. Forexample, the head of a patient may be positioned to a treating positionor mask-mounting position (as previously described) on the treatmentcouch 101 regardless of the height of the patient. In one embodiment,the drive mechanism including the offset single ball screw may allow theleg rest to travel up to approximately 22 inches in the x-direction 106.In another embodiment, the drive mechanism may allow the leg rest totravel up to approximately 28 inches. Alternatively, the drive mechanismmay allow the leg rest to travel up to approximately 45 inches. Itshould be noted that this distance may be longer, depending on thelength of the treatment couch 101. It should be noted, however, that inother non-treatment applications, the leg rest and corresponding drivemechanism may be designed to allow travel of the leg rest up to longerdistances without departing from the scope of this invention.

The embodiments described herein may accommodate a majority of differingheights of people, such as a range from one percentile female (e.g.,58.1 inches) to the ninety-nine percentile male (e.g., 75.6 inches).Motorized ball screws are known by those of ordinary skill in the art,and accordingly, additional details regarding their operation andconfigurations have not been included so as to not obscure theembodiments of the present invention.

FIG. 5 illustrates one embodiment of a drive mechanism including dualmotorized ball screw drive system 500, including one motor, mounted onoff-center lines of the treatment couch. The dual motorized ball screwdrive system 500 includes motor 201, belts 502, 503, and 504, ball screw402 and 501, and ball screw nuts 508 and 509. The dual motorized ballscrew drive system 500 is used to convert rotational motion of the motor201 about the axis 512 into linear motion of the leg rest 102 ortreatment couch 101 in the x-direction 106. Motor 201 is mounted totreatment couch 101 via mounting device 505. Mounting device 505 mayinclude an additional drive shaft 511, to translate the rotation of belt503 to belt 504. Belt 502 is coupled to the ball screw 501 and the motor201 (e.g., drive shaft 211). Belt 503 is coupled to the motor 201 (e.g.,drive shaft 211), and the additional drive shaft 511. Belt 504 iscoupled to belt 503, via the additional drive shaft 511, and to ballscrew 402. The motor 201 rotates one end of the belts 502 and 503 viadrive shaft 211. The other end of belt 502 rotates the ball screw 501.The other end of belt 503 rotates the additional drive shaft 511. Theadditional drive shaft 511 rotates one end of the belt 504. The otherend of belt 504 rotates the ball screw 402.

The dual ball screws (e.g., 402 and 501) may be mounted to the treatmentcouch 101 on off-center lines 406 and 506 of the treatment couch 101.The off-center line 406 may be a first offset distance 407 from thecenterline 305 of the treatment couch 101. The offset line 506 may be asecond offset distance 507 from the centerline 305 of the treatmentcouch 101. In one exemplary embodiment, the offset distances 407 and 507may have a range of approximately zero to approximately twelve inchesfrom the centerline 305. Alternatively, other offset distances may beused. The dual ball screws 402 and 501 may be mounted to the externalsurface of the treatment couch 101 using mounting device 308.Alternatively, as illustrated in FIG. 5, the dual ball screws 402 and501 and their corresponding assemblies may be embedded within thetreatment couch 101 using mounting device 308.

Ball screw nuts 508 and 509 include a hole in which the ball screwspass. The surface of the ball screw (e.g., 402 and 501) include groovesor threads, and the ball screw nuts (e.g., 508 and 509) include ballbearings (e.g., recirculating channel of balls) that pass through thegrooves or threads of the ball screws 402 and 501 to facilitate motionof the ball screw nut along the ball screw. As the ball screws arerotated by motor 201 via belts 502, 503, and 504, ball screw nuts 508and 509 move along the dual ball screw 402 and 501 relative to thehead-end 105 of the treatment couch 101 in the x-direction 106. Ballscrew nuts 508 and 509 are coupled to a slide member 306, which iscoupled to the leg rest 102. As the ball screw nuts 508 and 509 movealong the dual ball screws 402 and 501, the leg rest 102 moves up anddown along the one translational direction, x-direction 106, relative tothe head-end 105 of the treatment couch 101, via slide member 306. Inother words, as the motor 201 rotates, motor 201 drives the belts, whichin turns rotates the ball screws, which in turn drive the cars in alinear, translational direction (e.g., 106), which in turn drives theleg rest 102 in a linear, translational direction (e.g., 106). Inanother embodiment, a regular drive screw may be used in place of theball screw. The regular drive screw and corresponding nut or carincludes threads to facilitate motion of the nut or car along the screw.Alternatively, other actuators known by those of ordinary skill in theart may be used in this configuration, such as a linear actuator, apneumatic cylinder, a regular drive screw driven by a stepper motor.

As previously described, due to the fact that the forces in theoff-center line mounting may be higher than forces in the centerlinemounting, the size of the drive mechanism and slide member may need tobe increased to compensate or overcome the offset imbalance. By usingtwo drives (e.g., ball screws) in parallel, the sizing of lead screws(e.g., ball screws) may be reduced. Using two drives in parallel mayalso result in reduced loads due to the lack of resulting moments. Usingtwo drives may allow other components of the drive mechanism to bereduced, such as the slide member 306, mounting devices 205 and 308. Inone embodiment, the ball screw(s) may by driven by one motor withconnecting belt(s). Alternatively, the ball screws(s) may be driven bytwo stepper motors. These stepper motors may be synchronized steppermotors. As previously mentioned, the ball screws may be regular drivescrews driven by stepper motors, a linear actuator, a pneumaticcylinder, or other actuators known by those of ordinary skill in theart.

In one embodiment, the drive mechanism including dual motorized ballscrews 402 and 501 may be used to adjust an upper-half of a patientrelative to the head-end 105 of the treatment couch 101. For example,the dual motorized ball screws 402 and 501 of FIG. 5 may be used toposition the leg rest 102 in multiple positions, such as a loadingposition, and one or more treating positions. The drive mechanismincluding the single motorized ball screw may position the patient tomultiple treating positions, which allows a patient to be positioned toa specific position on the treatment couch 101 regardless of the heightof the patient. For example, the head of a patient may be positioned toa treating position or mask-mounting position (as previously described)on the treatment couch 101 regardless of the height of the patient. Inone embodiment, the drive mechanism including the dual motorized ballscrews may allow the leg rest to travel up to approximately 24 inches inthe x-direction 106. In another embodiment, the drive mechanism mayallow the leg rest to travel up to approximately 28 inches.Alternatively, the drive mechanism may allow the leg rest to travel upto approximately 45 inches. It should be noted that this distance may belonger, depending on the length of the treatment couch 101. It should benoted, however, that in other non-treatment applications, the leg restand corresponding drive mechanism may be designed to allow travel of theleg rest up to longer distances without departing from the scope of thisinvention.

The embodiments described herein may accommodate a majority of thediffering heights of people, such as a range from one percentile female(e.g., 58.1 inches) to the ninety-nine percentile male (e.g., 75.6inches). Motorized ball screws are known by those of ordinary skill inthe art, and accordingly, additional details regarding their operationand configurations have not been included so as to not obscure theembodiments of the present invention.

FIG. 6A illustrates another embodiment of a drive mechanism includingdual motorized ball screw drive system 600, including two motors,mounted on off-center lines of the treatment couch. The dual motorizedball screw drive system 600 of FIG. 6A includes motors 601 and 602,belts 603 and 604, multiple pulleys 605, ball screw 606 and 607, andcars 608 and 609. The dual motorized ball screw drive system 600 is usedto convert rotational motion of the motors 601 and 602 about axis 612(1)and axis 612(2) into linear motion of the leg rest 102 or treatmentcouch 101 in the x-direction 106. Motors 601 and 602 are embedded withintreatment couch 101. Alternatively, motors 601 and 602 may be mounted tothe external surface of the treatment couch 101. Belts 603 and 604 arecoupled to the motors 601 and 602, respectively. Pulleys, such as pulley605, may be used to couple the motors and belts. For example, pulley 605may be coupled to a drive shaft that extends from the motors 601 and602. Alternatively, the belts may couple directly to the motor. Belts603 and 604 are coupled to ball screws 606 and 607, respectively.Pulleys, such as pulley 605, may also be used to couple the belts andthe ball screws 606 and 607. For example, pulley 605 may be coupled toend of the ball screws 606 and 607 and the belts 603 and 604.Alternatively, the belts may couple directly to the ball screws. In oneembodiment, belts 603 and 604 may include teeth to prevent the ballscrew from slipping.

Motors 601 and 602 rotate one end of the belts 603 and 604 via driveshafts and pulleys. The other end of belt 603 rotates the ball screw606. The other end of belt 604 rotates the ball screw 607. The dual ballscrews (e.g., 606 and 607) may be mounted to the treatment couch 101 onoff-center lines 406 and 506 of the treatment couch 101. The offset line406 may be a first offset distance 407 from the centerline 305 of thetreatment couch 101. The offset line 506 may be a second offset distance507 from the centerline 305 of the treatment couch 101. In one exemplaryembodiment, the offset distances 407 and 507 may have a range ofapproximately zero to approximately twelve inches from the centerline305. Alternatively, other offset distances may be used. The dual ballscrews 606 and 607 may be mounted to the external surface of thetreatment couch 101 using mounting device 308. Alternatively, asillustrated in FIG. 5, the dual ball screws 606 and 607 and theircorresponding assemblies may be embedded within the treatment couch 101using mounting device 308.

In one embodiment, the motors 601 and 602 are stepper motors.Alternatively, other motors known by those of ordinary skill in the artmay be used, such as servomotors or other additional motors withencoders. Motors 601 and 602 may also be synchronized. The steppermotors may run open loop. In another embodiment, brakes may be appliedto the motors to stop the leg rest in the event of a power failure or inresponse to an operator command.

Ball screw nuts 608 and 609 include a hole in which the ball screwspass. The surface of the ball screws (e.g., 606 and 607) include groovesor threads, and the ball screw nuts (e.g., 608 and 609) include ballbearings (e.g., recirculating channel of balls) that pass through thegrooves or threads of the ball screws 606 and 607 to facilitate motionof the ball screw nut along the ball screw. As the ball screws 606 and607 are rotated by motors 601 and 602 via belts 603 and 604, and pulleys605, cars 608 and 609 move along the dual ball screw 606 and 607relative to the head-end 105 of the treatment couch 101 in thex-direction 106. Ball screw nuts 608 and 609 may be coupled to a slidemember 306, which is coupled to the leg rest 102. Alternatively, ballscrew nuts 608 and 609 may be coupled directly to the leg rest 102. Asthe ball screw nuts 608 and 609 move along the dual ball screws 606 and607, the leg rest 102 moves up and down along the one translationaldirection, x-direction 106, relative to the head-end 105 of thetreatment couch 101 (e.g., via slide member 306). In other words, as themotor rotates, the motor drives the belt, which in turns rotates theball screw, which in turn drives the car in a linear, translationaldirection (e.g., 106), which in turn drives the leg rest 102 in alinear, translational direction (e.g., 106). In another embodiment, aregular drive screw may be used in place of the ball screw. The regulardrive screw and corresponding nut or car includes threads to facilitatemotion of the nut or car along the screw. Alternatively, other actuatorsknown by those of ordinary skill in the art may be used in thisconfiguration, such as a linear actuator, a pneumatic cylinder, aregular drive screw driven by a stepper motor.

The drive mechanisms of FIG. 6A also includes two rail slides 610 and611. Rail slides 610 and 611 may be used to guide the cars 608 and 609along the ball screws 606 and 607. In another embodiment, the drivemechanism may include rail slides and linear guides to facilitate thelinear motion of the cars along the ball screws.

As previously described, due to the fact that the forces in theoff-center line mounting may be higher than forces in the centerlinemounting, the size of the drive mechanism and slide member may need tobe increased to compensate or overcome the offset imbalance. By usingtwo drives (e.g., ball screws) in parallel, the sizing of lead screws(e.g., ball screws) may be reduced. Using two drives in parallel mayalso result in reduced loads due to the lack of resulting moments. Usingtwo drives may allow other components of the drive mechanism to bereduced, such as the slide member 306, mounting devices 205 and 308. Inone embodiment, the ball screw(s) may by driven by one motor withconnecting belt(s). Alternatively, the ball screws(s) may be driven bytwo stepper motors, as illustrated in FIG. 6A. These stepper motors maybe synchronized stepper motors. As previously mentioned, the ball screwsmay be regular drive screws driven by stepper motors, a linear actuator,a pneumatic cylinder, or other actuators known by those of ordinaryskill in the art.

In one embodiment, the drive mechanism including dual motorized ballscrews 606 and 607 may be used to adjust an upper-half of a patientrelative to the head-end 105 of the treatment couch 101. For example,the dual motorized ball screws 606 and 607 of FIG. 6A may be used toposition the leg rest 102 in multiple positions, such as a loadingposition, and one or more treating positions. The drive mechanismincluding the single motorized ball screw may position the patient tomultiple treating positions, which allows a patient to be positioned toa specific position on the treatment couch 101 regardless of the heightof the patient. For example, the head of a patient may be positioned toa treating position or mask-mounting position (as previously described)on the treatment couch 101 regardless of the height of the patient.

In one embodiment, the drive mechanism including the dual motorized ballscrews may allow the leg rest to travel up to approximately 24 inches inthe x-direction 106. In another embodiment, the drive mechanism mayallow the leg rest to travel up to approximately 28 inches.Alternatively, the drive mechanism may allow the leg rest to travel upto approximately 45 inches. It should be noted that this distance may belonger, depending on the length of the treatment couch 101. It should benoted, however, that in other non-treatment applications, the leg restand corresponding drive mechanism may be designed to allow travel of theleg rest up to longer distances without departing from the scope of thisinvention.

The embodiments described herein may accommodate a majority of differingheights of people, such as a range from one percentile female (e.g.,58.1 inches) to the ninety-nine percentile male (e.g., 75.6 inches).Motorized ball screws are known by those of ordinary skill in the art,and accordingly, additional details regarding their operation andconfigurations have not been included so as to not obscure theembodiments of the present invention.

The treatment couch 101 of FIG. 6A includes a mounting area 612.Mounting area 612 may be used to mount the treatment couch 101 to astand, a robotic arm, or to other motorized mechanisms known by those ofordinary skill in the art to support and/or position a patient. In oneembodiment, a mounting extension area (e.g., 104) may be coupled to themounting area 612, as described below with respect to FIG. 6B.

FIG. 6B illustrates the drive mechanism of FIG. 6A including anextension mounting area. The treatment couch 101 of FIG. 6B includes amounting area 612. In one embodiment, extension mounting area 104 ismounted to the mounting area 612. Extension mounting area 104 may beused to attach mounting plate 613 at an off-center position 614.Alternatively, mounting plate 613 may be coupled to the mounting area612 at a center position 615. In one embodiment, mounting plate 613 iscoupled to a robotic arm having multiple degrees of freedom.Alternatively, the mounting plate 613 may be coupled to a stand or to amotorized mechanism for positioning a patient, or other known equipmentknown by those of ordinary skill in the art used to support and/orposition a patient.

It should be noted that the drive mechanisms of the embodimentsdescribed herein may be controlled by a controller. The controller maybe a manual mechanical controller, an electronic controller, or acomputerized controller. The controller may be a hand crank, a handcontroller (e.g., a hand-held pendant or remote control), or othercontrollers known by those of ordinary skill in the art. In oneexemplary embodiment, the controller may be the controller of a roboticarm having multiple degrees of freedom, and in essence, thetranslational motion of the leg rest 102 becomes an additional degree offreedom or axis of articulation. Alternatively, the leg rest 102 may becontrolled by other motorized mechanisms known by those of ordinaryskill in the art.

FIG. 7A illustrates one embodiment of a treatment couch including a legrest with one pivot point. Patient positioning system 700 includestreatment couch 101, leg rest 102, and extension mounting area 104.Treatment couch 101 is coupled to the leg rest 102 and extensionmounting area 104. In one embodiment, leg rest 102 includes one pivotpoint, such as hip pivot point 701. Hip pivot point 701 facilitates arotational motion (e.g., tilting motion) of the leg rest 102. The legrest 102 supports the lower-half of the patient's body while loading andtreating the patient. The leg rest 102 may move in a y-rotationaldirection 705 about the pivot axis 703. Leg rest 102 may also be coupledto a drive mechanism (e.g., 103) to facilitate translational motion(e.g., sliding or lifting motion) in the x-direction 106, as in otherembodiments described herein. The tilting motion of the leg rest 102 inthe y-rotational direction 705 about pivot axis 703 may be causedmanually or motorized. For example, the leg rest 102 may be coupled to amotorized mechanism, such as a motor or gearbox. Alternatively, thetilting motion may be done manually by an operator, such as with anon-motorized mechanical device (e.g., hand crank) or using his/herhands.

In one embodiment, a manual mechanical controller may be used to movethe leg rest in a translational direction, such as a manual ratchetdevice, similar to those found in folding chaises of a lounge chair. Asthe leg rest is rotated upwards, it locks at set intervals. The leg restmay need to be rotated to its extreme in order to be reset. In anotherembodiment, an electronic button or buttons may be placed on the side ofthe leg rest. The electronic button(s) may be directly wired to themotors to control the movement of the leg rest. Alternatively, othernon-computerized (e.g., manual and/or electronic) controllers known bythose of ordinary skill in the art may be used.

In one embodiment, a computerized mechanical controller may be used tomove the leg rest in a translational direction. The motor(s) may bewired back to a computerized controller that could manipulate the pivotpoints as additional axes. In one embodiment, the leg rest 102 may becoupled to a controller, and the controller may control the rotation(e.g., tilting motion) of the leg rest 102 about pivot axis 703 via amotorized mechanism, such as a gearbox. In one exemplary embodiment, thecontroller may be the controller of a robotic arm that is coupled to thetreatment couch, and the rotations of the pivot point(s) may beadditional axis or axes of the robotic arm for positioning a patient,both on the treatment couch and within a treatment room with respect toa radiation source. Alternatively, other computerized controller knownby those of ordinary skill in the art may be used.

FIG. 7B illustrates another embodiment of a treatment couch including aleg rest with two pivot points. Patient positioning system 710 includestreatment couch 101, leg rest 102, and extension mounting area 104.Treatment couch 101 is coupled to the leg rest 102 and extensionmounting area 104. In one embodiment, leg rest 102 includes two pivotpoints, such as hip pivot point 701 and knee pivot point 702. Hip pivotpoint 701 facilitates a first rotational motion (e.g., tilting motion)of the leg rest 102. Knee pivot point 702 facilitates a secondrotational motion (e.g., titling motion) of the leg rest 102. The legrest 102 supports the lower-half of the patient's body while loading andtreating the patient. The leg rest 102 may move in a first y-rotationaldirection 707 about the pivot axis 703 and in a second y-rotationaldirection 706 about the pivot axis 704. Leg rest 102 may also be coupledto a drive mechanism (e.g., 103) to facilitate translational motion(e.g., sliding or lifting motion) in the x-direction 106, as in otherembodiments described herein. The tilting motion of the leg rest 102 inthe z-direction 707 and 706 about pivot axes 703 and 704, respectively,may be caused manually or motorized. For example, the leg rest 102 maybe coupled to a motorized mechanism, such as a motor or gearbox.Alternatively, the tilting motion may be done manually by an operator,such as with a non-motorized mechanical device (e.g., hand crank) orusing his/her hands. In one exemplary embodiment, the leg rest 102 maybe coupled to a controller, and the controller may control the rotation(e.g., tilting motion) of the leg rest 102 about pivot axes 703 and 704via a motorized mechanism, such as a gearbox. It should be noted thatalthough the leg rest illustrated in FIG. 7B includes two pivot points,alternatively, more than two pivot points may be used.

FIG. 7C illustrates a single articulation of the one pivot point of theembodiment of FIG. 7A. The leg rest 102 of FIG. 7A includes one pivotpoint 701, which rotates about pivot axis 703. The single articulation700 of the one pivot point 701 allows the leg rest 102 to move in arotational direction, tilting motion 709, about pivot axis 703. Inanother embodiment, the leg rest 102 may move in the tilting motion 709and in a translational motion 711 relative to the head-end of thetreatment couch 101. The single articulation 700 of FIG. 7C may includea motorized or manual pivot point to move the leg rest 102 in tiltingand translational motions 709 and 711, respectively.

FIG. 7D illustrates a double articulation of the two pivot points of theembodiment of FIG. 7B. The leg rest 102 of FIG. 7B includes two pivotpoints 701 and 702, which rotate about pivot axis 703 and pivot axis704, respectively. The double articulation 710 of the two pivot points701 and 702 allow the leg rest 102 to move in two rotational directions,first and second tilting motions 709 and 712, about pivot axes 703 and704. In another embodiment, the leg rest 102 may move in the first andsecond tilting motions 709 and 712, and in a translational motion 711relative to the head-end of the treatment couch 101. The doublearticulation 710 of FIG. 7D may include motorized or manual pivot pointsto move the leg rest 102 in the first and second tilting andtranslational motions 709, 712, and 711, respectively.

In one embodiment, the first and second tilting motions 709 and 710about pivot axes 703 and 704 may be independent motions. Alternatively,the second tilting motion 710 may follow the first tilting motionthrough a linkage. The linkage may be a rigid link between the two partsof the leg rest that move and may be used to keep a portion of the legrest, which is below the knee pivot, at a fixed angle relative to thetable top while the angle of a second portion of the leg rest, which isabove the knee pivot, is rotating about pivot axis 703. In oneembodiment, the dual articulation 710, having two pivot points, may beused to flatten the leg rest 102 with respect to the plane of thetreatment couch 101. In other words, the double articulation 710, havingtwo pivot points 701 and 702, may permit the leg rest 102 to bepositioned substantially flat with respect to a plane of a top surfaceof the treatment couch 102 in substantially flat position 708. This mayallow the leg rest 102 to remain attached to the treatment couch 101during prone treatments of which, normally, the leg rest 102 would beremoved. For example, in prone treatments the leg rest at pivot point702 may push right into the patient's knees.

FIG. 8 illustrates one embodiment of a treatment couch including a baseportion and a plurality of detachable portions. Treatment couch 101 ofFIG. 8 includes a base portion 801, and a plurality of detachableportions 802(1)-(N) (e.g., multiple back-rests) of the treatment couch101. One detachable portion 802(1) of the plurality of detachableportions 802(1)-(N) is coupled to the base portion 801 of the treatmentcouch 101. Each detachable back-rest 802 has a height 804. The pluralityof detachable portions 802 (e.g., multiple back-rests) may be used toadjust a height of the treatment couch 101 to accommodate differingheights of patients. In one embodiment, the plurality of detachableportions 802 are used to position a head of a patient with respect to ahead-end 105 of the treatment couch 101. In another embodiment, theplurality of detachable portions 802 are used to adjust an upper-half ofa patient relative to a head-end 105 of the treatment couch 101.

In one embodiment, the treatment couch 101 of FIG. 8 may include a legrest 102. Leg rest 102 may be detachable, and may have one or more pivotpoints for one or more articulations, as described with respect to FIGS.7A-7D. Leg rest 102 may be coupled to extension mounting area 104.Alternatively, the treatment couch 101 of FIG. 8 may not include the legrest 102 and/or the extension mounting area.

In one embodiment, the base portion 801 of the treatment couch 101 maybe coupled to a robotic arm. Alternatively, the base portion 801 may becoupled to a stand, or to other motorized mechanisms known by those ofordinary skill in the art.

The multiple back-rests (e.g., the plurality of detachable portions 802)of treatment couch 101 may be mounted to the base portion 801. In oneembodiment, the multiple back-rests 802 may include a tab portion 803that is inserted into the base portion 801. The tab portion 803 may beused to easily remove the back-rests 802 from the base portion 801, tochange the height 804 of the treatment couch 101.

The multiple back-rests may minimize the range of adjustment necessaryfor any given patient. One of the multiple back-rests may be alarge-sized back-rest to accommodate the ninety-nine percentile male(e.g., 75.6 inches), and another a small-sized back-rest to accommodatethe one percentile female (e.g., 58.1 inches). Additional back-restsbetween the large-sized and the small-sized back-rests may also beprovided to accommodate differing heights of patients ranging betweenthe 99 ninety-nine percentile male (e.g., 75.6) and one percentilefemale (e.g., 58.1 inches). The more differing-heights back-rests thatare available, the lower the distance necessary for adjustment of thepatient's head relative to the head-end of the treatment couch. Themultiple back-rests may be stored on a rack on the wall of a treatmentroom. Alternatively, the multiple back-rests may be stored in otherplaces inside or outside of the treatment room.

FIG. 9A illustrates one embodiment a patient positioning system,including a treatment couch, a motorized leg rest, and a robotic arm,and a patient at two positions on the treatment couch while thetreatment couch is in a non-horizontal loading position. Patientpositioning system 900 includes treatment couch 101, motorized leg rest102, and robotic arm 903. Robotic arm 903 couples to the leg rest viamounting plate 907 to a mounting area on the treatment couch 101.Alternatively, treatment couch 101 may include an extension mountingarea (e.g., 104) to which the robotic arm 903 is mounted. Robotic arm903 may include multiple degrees of freedom. In one exemplaryembodiment, the robotic arm may include 6 degrees of freedom. In anotherexemplary embodiment, the robotic arm 903 may include componentsmanufactured by KUKA Roboter GmbH of Germany. Alternatively, the roboticarm 903 may have less than 6 degrees of freedom, and may utilize othermotorized mechanisms known by those of ordinary skill in the art used toposition a treatment couch.

Treatment couch 101 of FIG. 9A may include a cushion 906 for the head ofthe patient 904. Cushion 906 may be secured to the treatment couch viamounting device 905. The cushion 906 provides support to the patient'shead and may slide in a translational direction relative to the head-end105 of the treatment couch 101. The cushion 906 may also be integratedinto the body of treatment couch 101. In another embodiment, themounting device 905 may be used to secure a mask for the patient 904.The mask may be used to secure the patient to the treatment couch 101 tolimit the mobility of the patient 904 during treatment.

Leg rest 102 of FIG. 9A may include a motorized drive mechanism to movethe leg rest 102 in a translational direction relative to the head-end105 of the treatment couch 101. In one embodiment, the motorized drivemechanism is a rack and pinion gear. In another embodiment, themotorized drive mechanism may be a single or dual ball screw drivesystem. Alternatively, the motorized drive mechanism may be other drivemechanisms as described herein, and other motorized drive mechanismsknown by those of ordinary skill in the art. The leg rest 102 may bedetachable. The leg rest 102 may also include one or more pivot pointsto facilitate one or more tilting motions about one or more tiltingaxes. The pivot points may be used to position the leg rest to besubstantially flat with respect to a plane of a top surface of thetreatment couch 101.

In one embodiment, the patient 904 may be loaded onto the treatmentcouch 101 in a first position, such as when the treatment couch 101 ispositioned in a non-horizontal position and the leg rest 102 is at aloading position 901. After loading the patient onto the treatment couch101, the drive mechanism may move the leg rest 102 from loading position901 to a treating position 902. Treating position 902 may be where thehead of the patient 904 is positioned towards the head-end 105 of thetreatment couch 101. In one exemplary embodiment, the distance (e.g.,908) between the head of the patient and the head-end 105 may have arange of approximately zero to six inches. After treatment is completed,the drive mechanism may move the leg rest 102 from the treating position902 to the loading position 901 for unloading the patient 904 from thetreatment couch 101.

FIG. 9B illustrates the embodiment of FIG. 9A while the treatment couchis in a horizontal treatment position. In this embodiment, the patient904 may be loaded onto the treatment couch in a first position, such aswhen the treatment couch 101 is positioned in a horizontal position andthe leg rest 102 is at a loading position 901. After loading the patientonto the treatment couch 101, the drive mechanism may move the leg rest102 from loading position 901 to a treating position 902. Treatingposition 902 may be in a position where the head of the patient 904 ispositioned towards the head-end 105 of the treatment couch 101, forexample, within six inches of the head-end 105 of the treatment couch.After treatment is completed, the drive mechanism may move the leg rest102 from the treating position 902 to the loading position 901 forunloading the patient 904 from the treatment couch 101.

In one embodiment, the leg rest 102 may be moved to adjust the patient904 to a treating position 902 from a loading position 901. Treatingposition 902 may be where the head of the patient 904 is positioned oraligned so that there is substantially no distance (distance 908)between the head of the patient and the head-end 105 of the treatmentcouch 101. In one exemplary embodiment, the distance 908 between thehead of the patient 904 and the head-end 105 for the treating position108 may have a range of approximately zero to six inches. This may allowa radiation source (not illustrated in FIG. 9A or 9B to be positionedwith respect to the head of the patient with minimal interference fromthe treatment couch 101, or without any interference from the treatmentcouch 101. For example, if a shorter patient (e.g., 1 percentile femaleheight of 58.1 inches) is loaded onto the treatment couch 101 inposition 107, the patient's head will not be aligned or positioned atthe top (e.g., head-end 105) of the treatment couch 101 because of theheight of the shorter patient. However, by moving the leg rest 102 ofthe treatment couch 101 towards the head-end 105 of the treatment couch101 (e.g., from position 107 to position 108), the patient's head maybecome aligned or positioned at the top (e.g., relative to the head-end105) of the treatment couch 101.

In one embodiment, the treatment couch 101, including a motorized legrest, is coupled to a robotic arm 903. The robotic arm 903 includes acontroller. The controller positions the treatment couch 101 in one ormore degrees of freedom, for example, in at least 5 degrees of freedom.In this embodiment, the motorized leg rest (e.g., leg rest 102 andcorresponding drive mechanism) may be controlled independent of themotions controlled by the controller of the robotic arm 903.Alternatively, the controller of the robotic arm 903 may be used tocontrol both the motions of the robotic arm 903 for positioning thetreatment couch 101 in a treatment room, and the motions of the leg rest102 for positioning the patient 904 on the treatment couch 101 (e.g.,positioning an upper-half of a patient 904 relative to a head-end 105 ofthe treatment couch 101).

FIG. 10A is a perspective drawing illustrating a patient in a firstposition of a workspace of a radiation treatment system including a setof spatial nodes at which to position the radiation source, inaccordance with an exemplary embodiment of the invention. Theillustrated embodiment of radiation treatment system 1000 includes aradiation source 1005, detectors 1015A and 1015B (collectively 1015,also referred to as imagers), imaging sources 1020A and 1020B(collectively 1020), and a robotic arm 1025.

The illustrated embodiment also includes a patient positioning system1060. Patient positioning system 1060 includes a treatment couch 101 anda stand 1080. Alternatively, treatment couch 101 may be coupled to arobotic arm (e.g., 903), or other motorized positioning system known bythose of ordinary skill in the art. Patient positioning system 1060includes leg rest 102. Leg rest 102 may be used to adjust an upper-halfof the patient 904 relative to a head-end of the treatment couch 101.Leg rest 102 may include a motorized mechanism for adjusting the patienton the treatment couch 101. Leg rest 102 may also include one or morepivot points as described herein. In this exemplary embodiment, thepatient 904 is positioned at position 1010. Position 1010 may be aloading position. The loading position may include the treatment couch101 being in a horizontal position, or alternatively, in anon-horizontal position.

Radiation treatment system 1000 may be used to perform radiationtreatment (e.g., radiosurgery and/or radiotherapy) to treat or destroy alesion (e.g., tumorous tissue) within a patient. During radiationtreatment, the patient rests on treatment couch 101, which is maneuveredto position a volume of interest (“VOI”) containing a target to a presetposition or within an operating range accessible to radiation source1005 (e.g., field of view). In one embodiment, radiation treatmentsystem 1000 is an image guided radiation treatment system. In oneexemplary embodiment, the radiation treatment system 1000 may be aframeless, image-guided robot-based therapeutic radiation treatmentsystem utilizing a linear accelerator (“linac”), such as the CyberKnife®system developed by Accuray, Inc. of California. Alternatively, thetherapeutic radiation treatment system 1000 may be a gantry-based(iso-centric) treatment system or other type of medical operationsystems. Together, imaging sources 1020 and detectors 1015 are animaging guidance system that provides visual control over the positionof treatment couch 101 and the patient thereon and the alignment ofradiation source 1005 with respect to the VOI within the patient. In oneembodiment, the patient positioning system treatment couch 101 may becoupled to a positioning system 1080 (not illustrated), such as roboticarm 903, that receives feedback from the imaging guidance system toprovide accurate control over both the displacement and orientation ofthe VOI within the patient relative to radiation source 1005. In anotherembodiment, positioning system 1080 may be a stand, as illustrated inFIGS. 10A and 10B, or a motorized positioning system known by those ofordinary skill in the art.

In one embodiment, robotic arm 1025 has multiple (e.g., six) degrees offreedom capable of positioning the radiation source 1005 with almost aninfinite number of positions and orientations within its operatingenvelope.

A collection of spatial nodes and associated safe paths interconnectingthese spatial nodes is called a “workspace” or “node set”. FIG. 10Aillustrates a workspace 1030, including a number of spatial nodes 1035each represented by a symbol (only a couple are labeled). Multipledifferent workspaces may be created and defined for different patientwork areas. For example, workspace 1030 may be spherical (asillustrated) and defined for treating VOIs residing within the head of apatient 904. Alternatively, workspace 1030 may have other geometries(e.g., elliptical) and defined for treating VOIs residing within otherareas of a patient. Additionally, multiple workspaces 1030 may bedefined for different portions of a patient, each having differentradius or source to axis distances (“SAD”), such as 650 mm and 800 mm.The SAD is the distance between the collimator lens in radiation source1005 and the target within the VOI. The SAD defines the surface area ofthe workspace. In one embodiment of an elliptical workspace, the SAD mayrange from 900 mm to 1000 mm. Other SADs may be used.

Spatial nodes 1035 reside on the surface of workspace 1030. Spatialnodes 1035 represent positions where the radiation source 1005 ispre-programmed to stop and delivery a dose of radiation to the VOIwithin the patient. During delivery of a treatment plan, robotic arm1025 moves radiation source 1005 to each and every spatial node 1035,where a dose is determined to be delivered, following a predefined path.The predefine path may also includes some spatial nodes 1035 where nodose needs to be delivered, in order to simplify the motions of therobotic arm.

FIG. 10A illustrates a node set including an exemplary number of spatialnodes 1035 (e.g., 100 to 115). The node set may include spatial nodes1035 substantially uniformly distributed over the geometric surface ofworkspace 1030. The node set includes all programmed spatial nodes 1035and provides a workable number of spatial nodes 1035 for effectivelycomputing treatment plan solutions for most ailments and associatedVOIs. The node set provides a reasonably large number of spatial nodes1035 such that homogeneity and conformality thresholds can be achievedfor a large variety of different VOIs, while providing enough vantagepoints to avoid critical structures within patients. It should beappreciated that the node set may include more or less spatial nodes1035 than is illustrated or discussed. For example, as processing powerincreases and experience gained creating treatment plans, the averagenumber of spatial nodes 1035 may increase with time to provide greaterflexibility and higher quality treatment plans.

FIG. 10A illustrates a patient 904 in a first position (e.g., 1010) ofworkspace 1030 of the radiation treatment system 1000 including a set ofspatial nodes 1035 at which to position the radiation source 1005. Inthis exemplary embodiment, the height of patient 904 is smaller than theheight of the treatment couch 101 from the head-end of the treatmentcouch 101 to the position of the leg rest 102. Because of the placementof the head of patient 904 the radiation source 1005 may be positionedat the exemplary spatial nodes 1035.

FIG. 10B is a perspective drawing illustrating the patient in a secondposition of the workspace of the radiation treatment system, inaccordance with the embodiment of FIG. 10B. As previously described withrespect to FIG. 10A, the height of patient 904 is smaller than theheight of the treatment couch 101 from the head-end of the treatmentcouch 101 to the position of the leg rest 102 when the patient is in thefirst position 1010. However, by moving the leg rest 102 by using amotorized mechanism, as described herein in the present embodiments,relative to the head-end 105 of the treatment couch 101, the head ofpatient 904 may be positioned at a second position 1020. Because thehead of the patient 904 is positioned closer to the head-end 105 of thetreatment couch 101 in second position 1020, the available spatial nodesincreases (e.g., increased spatial nodes 1065), as illustrated as dashed“+” in FIG. 10B. When the patient is positioned or aligned to thehead-end 105 of the treatment couch 101 (e.g., position 1020), theavailable number of spatial nodes 1035 of workspace 1070 of FIG. 10B,which includes spatial nodes 1035 and increased spatial nodes 1065, isgreater than the number of available number of spatial nodes ofworkspace 1030 when the patient is positioned at the first position1010. In other words, by adjusting the patient (e.g., upper-half of thepatient) relative to the head-end 105 of the treatment couch 101, theavailable workspace 1070 (e.g., including the increased number ofspatial nodes 1065) of the radiation source 1005 of radiation treatmentsystem 1000 is increased. By moving the patient from the first position1010 to the second position 1020, the radiation source 1005 may accesscertain zones (e.g., spatial nodes) near the treatment couch 101 thatwere previously blocked by the treatment couch 101 when the patient wasin the first position 1010. Having greater accessibility to thosecertain zones, which were previously blocked by the treatment couch 101,increases the workspace 1070 (e.g., spatial nodes at which the radiationsource 1005 may deliver radiation to the target).

FIG. 11A and FIG. 11B are elevational side and elevational end viewsillustrating a cross-section of a workspace of a radiation treatmentsystem including a node set and an increased node set, in accordancewith an embodiment of the invention. Cross-sections 1100A and 1100Billustrate how a node set of workspace 1070 may have spatial nodes 1035and increased spatial nodes 1065 evenly distributed around its surface.Other distributions are possible.

Using large or complete node sets of spatial nodes 1035 and increasedspatial nodes 1065 may increase flexibility to achieve conformality andhomogeneity, while minimizing risk of complications to a patient for awide variety of different VOIs. A larger node set provides a greaternumber of vantage points from which to delivery a radiation beam fromradiation source 1005. The greater the number of vantage points thegreater the flexibility to design a treatment plan that avoids beamtrajectories passing close to or through critical structures of apatient. Avoiding proximity to critical structures reduces the risks ofcomplication to a patient.

In one embodiment, the node set of workspace 1030 (as illustrated inFIG. 10A) may be increased to be an increased node set of workspace 1070(as illustrated and described with respect to FIG. 10B). By moving oradjusting the upper-half of patient 904 from a first position 1010 to asecond position 1020, the number of node sets 1035 may increase (e.g.,by increased spatial nodes 1065). Because the head of the patient 904 ispositioned closer to the head-end 105 of the treatment couch 101 insecond position 1020 than in the first position 1010, the availablespatial nodes increases (e.g., increased spatial nodes 1065), asillustrated as dashed “+” in FIGS. 11A and 11B. For example, workspace1070 includes spatial nodes 1035 and increased spatial nodes 1065 whenthe patient 904 is positioned at the second position 1020, while theworkspace 1030 includes only node set 1035 when the patient 904 ispositioned at the first position 1010.

In one exemplary embodiment, the leg rest may be used when acquiring apre-treatment image (e.g., a magnetic resonance (MR) image, acomputerized tomography (CT) image, fluoroscopy image, and a positronemission tomography (PET) image) of a patient in a pre-treatmentposition (including the treating position) for treatment planningpurposes. The pre-treatment position may be recorded electronically ormechanically at the time of acquiring the pre-treatment image, andmanually or automatically loaded to restore the same leg rest positionduring treatment. This may be done not only to ensure positioning withrespect to the pre-treatment position, but also, to ensure consistenttreating positions across multiple fractions (e.g., multiple treatmentsof the patient).

Restoration of the pre-treatment position may be used to aid inregistration of the patient. Registration of a patient using a radiationsystem may be used in an initial patient setup as a positioningprocedure for aligning a patient to be in a same position as when thepatient was imaged during treatment planning. During treatment planning,pre-treatment images (as an initial reference image) of the patient aretaken and used to plan radiation to be delivered by the radiationsource. Subsequent images (e.g., treatment images) are then registeredwith the pre-treatment image in order to determine the location ordisplacement of the target (e.g., tumor) with respect to thepre-treatment scan (initial reference image). The displacement of thetarget determined by the registration may be used to adjust the patientposition such that the displacement is minimized to within an operatingrange of the radiation treatment system. This enables the radiationsource to be controlled to deliver radiation beams as specified by thetreatment plan. After the patient is positioned during the initialpatient setup, then the radiation may be delivered to the target of thepatient from the radiation source.

Restoration of the pre-treatment position, or intra-fraction treatmentpositions, may be particularly helpful with a non-image guided radiationsystem, which relies on precise target alignment with the radiationsource, as opposed to an image-guided radiation system, which enablesthe radiation source manipulator to track and correct for changes inpatient target position during treatment delivery.

Restoration of the pre-treatment position may also be used to aid inimmobilization of the patient. Immobilization may be used to maintain aconstant spatial relationship between the target and the radiationsource to ensure accurate dose delivery. Immobilization may be affectedby the positioning of the patient on the treatment couch. Thus,restoration of the leg rest to a same position as a pre-treatmentposition may help immobilize the target with respect to a skeletalstructure of the body, thereby, minimizing or eliminating tumordeformation and displacement. For example, during treatment of a targetwith the sacrum region, when a patient is positioned on the treatmentcouch, the patient's skeletal structure and organs comes to rest.However, by changing the position of the legs (e.g., tilting the legs ata different angle), the target (e.g., tumor) may change by displacementor by deformation based on how the legs are positioned with respect tothe skeletal structure. This may be used for both image-guided andnon-image-guided radiation treatment systems.

In one embodiment, a method for positioning a patient on a treatmentcouch may include loading a patient onto a treatment couch, in a firstoperation. In a second operation, mechanically adjusting an upper-halfof the patient relative to a head-end of the treatment couch. In oneembodiment, adjusting the upper-half of the patient may be done beforeloading the patient onto the couch. Alternatively, the adjusting may bedone after loading the patient onto the couch. The method may furtherinclude positioning the patient in a treatment room or with respect to aradiation source in a treatment position. It should be noted that thepatient may be positioned in a treatment room or with respect to theradiation source before or after the patient has been adjusted on thetreatment couch relative to the head-end. Alternatively, both operationsmay be performed at substantially the same time. For example, after thepatient is loaded onto the couch, the patient may be positioned on thecouch relative to the head-end of the treatment couch while thetreatment couch is positioned in a treatment room relative to aradiation source of a radiation treatment system.

Mechanically adjusting the upper-half of the patient may include movingthe upper-half of the patient using a motorized drive mechanism. Themotorized drive mechanism may be a rack and pinion gear. Alternatively,the motorized drive mechanism may be a single ball screw drive, such asa telescopic ball screw drive, or a dual ball screw drive. The motorizeddrive mechanisms may be mounted on a centerline of the treatment couchor in an off-center line, having an offset from the centerline of thetreatment couch. Alternatively, other motorized drive mechanisms may beused to adjust the upper-half of the patient.

In another embodiment, mechanically adjusting the upper-half of thepatient may include moving the upper-half of the patient using a manualdrive mechanism. The manual drive mechanism may be a hand crank or othermechanical device known by those of ordinary skill in the art.

In another embodiment, the method may further include providing a legrest, which has a single pivot point, to be coupled to the treatmentcouch, in a third operation. In a fourth operation, the method mayinclude rotating or tilting the leg rest about a pivot axis of the pivotpoint. Alternatively, the method may include providing a leg rest, whichhas multiple pivot points, to be coupled to the treatment couch, in athird operation; and in a fourth operation, rotating or tilting the legrest about the multiple pivot axes of the multiple pivot points. In oneexemplary embodiment, the multiple pivot points may be used to positionthe leg rest to be substantially flat with respect to a plane of a topsurface of the treatment couch. Having the leg rest be substantiallyflat with respect to the treatment couch may allow the leg rest frombeing removed for prone treatments. In one embodiment, the method mayinclude positioning the leg rest to be substantially flat with respectto a plane of a top surface of the treatment couch, in a thirdoperation.

The method may further include detaching the leg rest from the treatmentcouch, in a fifth operation. In some embodiments, the leg rest may beremoved for prone treatments or so that it is not in the way of theradiation source or other objects used in the treatment.

In another embodiment, the treatment couch may include a base portionand a plurality of detachable portions, of which one, is coupled to thebase portion at a time. The method, implementing this design, mayfurther include detaching a first detachable portion from a base portionof a treatment couch, in a third operation. The method may also includeattaching a second detachable portion to the base portion to adjust aheight of the treatment couch to accommodate differing heights ofpatients, in a fourth operation.

In another embodiment, the treatment couch may include a base portionand a back-rest portion coupled to the base portion, and the method mayfurther include adjusting the upper-half of the patient comprisesadjusting a height of the back-rest portion of the treatment couch toaccommodate differing heights of patients, in a third operation.

The embodiments described herein may also be implemented in a treatmentcouch of a patient positioning system, used in connection with aradiation treatment system. In one embodiment, the radiation treatmentsystem may be a robot-based linear accelerator treatment system.Alternatively, the radiation treatment system may be a gantry-basedradiation treatment system.

The patient positioning system may include a treatment couch coupled toa stand, or alternatively, to a positioning system. In one embodiment,the positioning system may be a robotic arm, having one or more degreesof freedom. Alternatively, the positioning system may be other motorizedmechanisms known by those of ordinary skill in the art used to positiona treatment couch.

In one embodiment, a method, implementing the patient positioning andradiation treatment systems, may include providing a treatment couchcoupled to a first robotic arm, in a first operation, moving thetreatment couch along one or more rotational degrees of freedom, in asecond operation, and moving an upper-half of a patient relative to ahead-end of the treatment couch, in a third operation. The method mayfurther include providing a linear accelerator coupled to a secondrobotic arm, the second robotic arm to move the linear accelerator withrespect to a treatment target of the patient, in a fourth operation. Themethod may further include providing an imaging system having an imagingfield of view, and maintaining the treatment couch substantially outsideof the imaging field of view for all supported treatment positions bymoving the upper-half of the patient relative to the head-end of thetreatment couch.

In another embodiment, the method may further include providing a legrest having a pivot point to be coupled to the treatment couch, in athird operation, and rotating or tilting the leg rest about the pivotpoint, in a fourth operation. Alternatively, the third and fourthoperations may include providing a leg rest having a having a pluralityof pivot points to be coupled to the treatment couch, and rotating ortilting the leg rest about the plurality of pivot points. In oneexemplary embodiment, the multiple pivot points may be used to positionthe leg rest to be substantially flat with respect to a plane of a topsurface of the treatment couch. Having the leg rest be substantiallyflat with respect to the treatment couch may allow the leg rest frombeing removed for prone treatments. In one embodiment, the method mayinclude positioning the leg rest to be substantially flat with respectto a plane of a top surface of the treatment couch, in a thirdoperation. The method may further include detaching the leg rest fromthe treatment couch in a fifth operation.

In another embodiment, the treatment couch may include a base portionand a plurality of detachable portions, of which one is coupled to thebase portion at a time. The method, implementing this design, mayfurther include detaching a first detachable portion from a base portionof a treatment couch, in a third operation. The method may also includeattaching a second detachable portion to the base portion to adjust aheight of the treatment couch to accommodate differing heights ofpatients, in a fourth operation.

In another embodiment, the treatment couch may include a base portionand a back-rest portion coupled to the base portion, and the method mayfurther include adjusting the upper-half of the patient comprisesadjusting a height of the back-rest portion of the treatment couch toaccommodate differing heights of patients, in a third operation. hereinadjusting the upper-half of the patient comprises adjusting theupper-half of the patient before/after or during loading the patientonto the treatment couch

It should be noted that the embodiments described herein are not limitedto radiation treatment systems. The embodiments described herein mayalso be used in connection with other medical treatment, such as apositioning couch for an operating room, a positioning couch for adiagnostic x-ray machine, a positioning chair for dental procedures,treatment chairs, and other medical patient support or positioningcouches.

As previously discussed, the embodiments described herein are notlimited to a treatment couch used for medical treatment. The embodimentsdescribed herein may also be used in connection with other non-medicaltreatment systems, such as a couch (which may otherwise be referred toas a chair, or otherwise, in particular fields of application) for asimulator, video or arcade game system. The embodiments described hereinmay also be used as a loading mechanism for an amusement park ride, formilitary machinery, or for heavy machinery to position, reposition,align, or adjust a body (e.g., human or animal body) into a confinedspace (e.g., into a gunner position of a tank) in a translationaldirection. Alternatively, the embodiments described herein may be usedin other types of applications that involve positioning a body withrespect to one end of a couch in a translational direction.

Embodiments of the present invention include various operations, whichwill be described below. These operations may be performed by hardwarecomponents, software, firmware, or a combination thereof. As usedherein, the term “coupled to” may mean coupled directly or indirectlythrough one or more intervening components. Any of the signals providedover various buses described herein may be time multiplexed with othersignals and provided over one or more common buses. Additionally, theinterconnection between circuit components or blocks may be shown asbuses or as single signal lines. Each of the buses may alternatively beone or more single signal lines and each of the single signal lines mayalternatively be buses.

Certain embodiments may be implemented as a computer program productthat may include instructions stored on a machine-readable medium. Theseinstructions may be used to program a general-purpose or special-purposeprocessor to perform the described operations. A machine-readable mediumincludes any mechanism for storing or transmitting information in a form(e.g., software, processing application) readable by a machine (e.g., acomputer). The machine-readable medium may include, but is not limitedto, magnetic storage medium (e.g., floppy diskette); optical storagemedium (e.g., CD-ROM); magneto-optical storage medium; read-only memory(ROM); random-access memory (RAM); erasable programmable memory (e.g.,EPROM and EEPROM); flash memory; electrical, optical, acoustical, orother form of propagated signal (e.g., carrier waves, infrared signals,digital signals, etc.); or another type of medium suitable for storingelectronic instructions.

Additionally, some embodiments may be practiced in distributed computingenvironments where the machine-readable medium is stored on and/orexecuted by more than one computer system. In addition, the informationtransferred between computer systems may either be pulled or pushedacross the communication medium connecting the computer systems.

A “target” as discussed herein may be an anatomical feature(s) of apatient such as a pathological anatomy (e.g., tumor, lesion, vascularmalformation, nerve disorder, etc.) or normal anatomy and may includeone or more non-anatomical reference structures.

It should be noted that the methods and apparatus described herein arenot limited to use only with medical diagnostic imaging and treatment.In alternative embodiments, the methods and apparatus herein may be usedin applications outside of the medical technology field, such asindustrial imaging and non-destructive testing of materials (e.g., motorblocks in the automotive industry, airframes in the aviation industry,welds in the construction industry and drill cores in the petroleumindustry) and seismic surveying. In such applications, for example,“treatment” may refer generally to the application of a beam(s) and“target” may refer to a non-anatomical object or area.

The controller(s) described herein may include one or moregeneral-purpose processing devices such as a microprocessor or centralprocessing unit, or the like. Alternatively, the controller may includeone or more special-purpose processing devices such as a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA), or the like. In an alternativeembodiment, for example, the controller may be a network processorhaving multiple processors including a core unit and multiplemicroengines. Additionally, the controller may include any combinationof general-purpose processing device(s) and special-purpose processingdevice(s).

Although the operations of the method(s) herein are shown and describedin a particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the invention asset forth in the appended claims. The specification and drawings are,accordingly, to be regarded in an illustrative sense rather than arestrictive sense.

What is claimed is:
 1. A method, comprising: providing a leg restcoupled to a couch; and mechanically adjusting an upper-half of a body,disposed on the couch, relative to a head-end of the couch by moving theentire leg rest along a longitudinal axis of the couch to move theupper-half of the body relative to the head-end of the couch withoutextending an upper edge of the leg rest beyond an upper edge of thecouch while the body is disposed on the couch.
 2. The method of claim 1,further comprising positioning a head of the body at the head-end of thecouch where there is substantially no space between the head and thehead-end of the couch.
 3. The method of claim 1, further comprisingpositioning a head of the body at the head-end of the couch where thereis a specified distance between the head of the patient and the head-endof the couch.
 4. The method of claim 1, wherein mechanically adjustingthe upper-half of the body comprises moving the leg rest using at leastone of a motorized drive mechanism or a manual drive mechanism.
 5. Themethod of claim 1, further comprising detaching the leg rest from thecouch.
 6. The method of claim 1, further comprising rotating the legrest about a pivot point of the leg rest.
 7. The method of claim 6,further comprises rotating the leg rest about one or more additionalpivot points of the leg rests.
 8. The method of claim 7, furthercomprising positioning the leg rest to be substantially flat withrespect to a plane of a top surface of the couch by rotating the legrest about at least one of the pivot point and the one or moreadditional pivot points.
 9. An apparatus, comprising: a couch; a legrest coupled to the couch; and a drive mechanism coupled to the legrest, the drive mechanism to move the entire leg rest along alongitudinal axis of the couch to move an upper-half of a body withrespect to a head-end of the couch, the drive mechanism to move the legrest between a loading position and a treating position of the couch.10. The apparatus of claim 9, wherein the drive mechanism is to positiona head of the body at the head-end of the couch where there issubstantially no space between the head and the head-end of the couch.11. The apparatus of claim 9, wherein the drive mechanism is to positiona head of the body at the head-end of the couch where there is aspecified distance between the head of the patient and the head-end ofthe couch.
 12. The apparatus of claim 9, wherein the drive mechanism isa motorized drive mechanism
 13. The apparatus of claim 12, wherein themotorized drive mechanism comprises a rack and pinion gear.
 14. Theapparatus of claim 12, wherein the motorized drive mechanism comprises asingle ball screw drive system coupled to the leg rest.
 15. Theapparatus of claim 14, wherein the single ball screw system comprises atelescopic ball screw.
 16. The apparatus of claim 12, wherein themotorized drive mechanism comprises at least one of a linear actuator, apneumatic cylinder, or a regular drive screw driven by a stepper motor.17. The apparatus of claim 12, wherein the motorized drive mechanismcomprises a dual ball screw drive system coupled to the leg rest. 18.The apparatus of claim 12, wherein the motorized drive mechanism ispositioned at a centerline of the couch.
 19. The apparatus of claim 12,wherein the motorized drive mechanism is positioned at an off-centerline, the off-center line having an offset distance from a centerline ofthe couch.
 20. The apparatus of claim 9, wherein the leg rest isdetachable.
 21. The apparatus of claim 9, wherein the leg rest comprisesa pivot point.
 22. The apparatus of claim 21, wherein the pivot point isa motorized pivot point.
 23. The apparatus of claim 21, wherein the legrest comprises one or more additional pivot points to permit the legrest to be positioned substantially flat with respect to a plan of a topsurface of the couch.
 24. The apparatus of claim 9, further comprising asliding member coupled to the leg rest, the sliding member to move withthe leg rest along the longitudinal axis of the couch, wherein thesliding member prevents the upper-half of the body from being pinchedbetween the leg rest and the couch as the leg rest moves along thelongitudinal axis.
 25. An apparatus, comprising: a couch having ahead-end; a leg rest coupled to the couch; and means for moving theentire leg rest along longitudinal axis of the couch to mechanicallyadjust an upper-half relative to the head-end of the couch and movingthe leg rest between a loading position and a treating position of thecouch.
 26. The apparatus of claim 25, wherein the leg rest is coupled tothe couch at a pivot point at an upper end of the leg rest, the upperend of the leg rest being closer to the head-end of the couch than alower end of the leg rest, and wherein the apparatus further comprisesmeans for rotating the leg rest about he pivot point.
 27. The apparatusof claim 25, wherein the leg rest comprises a plurality of pivot points,and wherein the apparatus further comprises means for rotating the legrest about the plurality of pivot points to position the leg rest to besubstantially flat with respect to a plan of a top surface of the couch.28. The apparatus of claim 25, further comprising means for positioningthe leg rest to be substantially flat with respect to a plan of a topsurface of the couch.
 29. The apparatus of claim 25, further comprisingmeans for detaching the leg rest from the couch.
 30. An apparatus,comprising: a treatment couch comprising: a base portion; and a ratchetportion of the treatment couch coupled to the base portion of thetreatment couch, the ratchet portion to adjust a height of the treatmentcouch to accommodate differing heights of bodies; a leg rest coupled tothe treatment couch; and a drive mechanism coupled to the leg rest, thedrive mechanism to move the entire leg rest along a longitudinal axis ofthe treatment couch to move the upper-half of the body relative to thehead-end of the treatment couch, the drive mechanism to move the legrest between a loading position and a treating position of the treatmentcouch.
 31. The apparatus of claim 30, wherein the leg rest isdetachable.
 32. The apparatus of claim 30, further comprising: aradiation treatment system comprising a radiation source; a patientpositioning system to position a patient with respect to the radiationsource of the radiation treatment system, the patient positioning systemcomprising the treatment couch, the leg rest, and the drive mechanism.